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Sunday, 24 November 2013

One of the standout pieces from the Bones Kickstarter has to be the big translucent Fire Elemental and it was always going to get some special treatment from me.

Reaper Bones Fire Elemental

Xanderhook on the Reaper Forums got there before me and his post comes highly recommended as an excellent tutorial in painting the transparent bones. I chose a slightly different route for my LEDs which required drastic plastic surgery!!

Disco Inferno

I picked up a fibre optic novelty lamp in the pound shop some weeks earlier, for another project, which I discovered had a neat design. 3 coloured LEDs (blue, green and red) mounted on a tiny circuit board with a momentary switch feeding a pulse to a chip which regulated the power from the 3 AA batteries to the LEDs.

The plan was simple:

Extricate the board from the housing.

Swap the batteries for Dry Cell (watch batteries) - as AAs are too big for the base.

Swap the 3 colour LEDs for Red ones with long wires which can be inserted into the mini.

Add a longer throw momentary button switch.

Pack it all into a custom 40mm MDF (Medium Density Fibreboard) base.

Tools and Supplies

To complete this project you'll need:

1 x translucent miniature

1 x base

3 x bright LEDs (I used red ones)

3 x dry cell batteries (I used 3v CR 2032) and holders

1 x momentary button switch (I got 20 on eBay for £1.50)

component wire

solder and flux

soldering iron

dremel hobby drill

craft knife

superglue

milliput or similar modelling putty

hot glue gun or insulation tape

Where to Drill and Cut

I wanted to embed 3 LEDs, one in each hands and one in the head, a scan of the mini showed that it was possible to drill holes from the elbow to the end of each hand and down between the shoulder blades and into the head area. Getting the wires through the mini was going to be difficult, but cutting the mini in half across it's waist meant I could get the wires up through the middle and out about half way up the back. This left the three pairs of wires branching out in an inverted arrow on the surface, untidy, but easily concealed with a bit of milliput.

Cut along the white line, Drill in the yellow direction

The Base

I made the base from three discs of 2.5mm MDF which I cut out roughly with the dremel and then mounted each disc to an arbour and sanded into a circle. The three rings were then cut out using a file to score the surface of the MDF as it spun on the arbor (WARNING... only use this method if you are using a dremel which spins at a slow speed otherwise you are highly likely to either fire the file into your hand or get an MDF frisbee in the head!!!). The safe method is to drill lots of holes around your inner ring and then join them up using a file. Once you have 4 parts glue together with super glue as in the diagram below.

Base Dimensions and Construction

Of course if you don't want to go through the hassle of making your own base out of MDF you could just use something like a coffee jar lid. Anything will do as long as it has enough space underneath for you to cram in all the components, like the battery holders wires and circuit board.

Keep Calm and Solder On

A soldering iron is a must have for this great little circuit bending project but they are a handy tool to have for those odd bits of electrical DIY and can be bought pretty cheaply these days.

Here's a closeup of the circuit from my fibre-optic lamp. You'll need to connect a pair of wires of appropriate length to each of the LEDs and work out (through trial and error) which leg needs to be soldered to which spot on the board, fortunately they are very close to each other so its not too tricky.

Fibre-optic lamp circuit showing major components

Once you've done that you can connect your batteries together in series to give yourself enough voltage to light all of the LEDs at the same time. There are plenty of videos on YouTube which show beginners how to
solder so I won't go into any specifics other than a few directions and
top tips.

Soldering LED legs neatly is tricky, I straddle the LED over a metal
ruler (as a third hand and then solder the wires on top. The ruler
dissipates the heat quite effectively and you get straight joints.

Use a hot glue gun to insulate your LED legs from each other other wise they won't light up.

Flux is a necessity, don't solder without it.

tin your wires before attempting to solder them to the circuit board.

Construction Video

Here's a video of the construction and more importantly the illumination effect.